666703397 has 4 divisors (see below), whose sum is σ = 667017516. Its totient is φ = 666389280.

The previous prime is 666703327. The next prime is 666703423. The reversal of 666703397 is 793307666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 793307666 = 2 ⋅396653833.

It can be written as a sum of positive squares in 2 ways, for example, as 135815716 + 530887681 = 11654^2 + 23041^2 .

It is a cyclic number.

It is not a de Polignac number, because 666703397 - 2¹⁸ = 666441253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666703307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153854 + ... + 158127.

It is an arithmetic number, because the mean of its divisors is an integer number (166754379).

Almost surely, 2^666703397 is an apocalyptic number.

It is an amenable number.

666703397 is a deficient number, since it is larger than the sum of its proper divisors (314119).

666703397 is a wasteful number, since it uses less digits than its factorization.

666703397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314118.

The product of its (nonzero) digits is 857304, while the sum is 47.

The square root of 666703397 is about 25820.6002447658. The cubic root of 666703397 is about 873.5965078925.

The spelling of 666703397 in words is "six hundred sixty-six million, seven hundred three thousand, three hundred ninety-seven".